Automatic gravity ladder-lock.



I. MYERS.

AUTOMATIC GRAVITY LADDER LOCK.

APPLICATION man NOV-23. i914.

1,210,827. Patented Jan. 2, 1917. WW

Z{- V I T2 AI 7 /.2 i 4 "w K /v H H 1/ :I' Z 3 Witnesses Z lnven'tor Attorneys one isrinnL MYERS, or GQSHEN, INDIANA, essieivon r0 THE summon-LADDER COMPANY,

or eosnnn, INDIANA.

Specificationof Letters Patent.

I Patented Jan. 2, 1917.

' Application filed November 23, 1914; Serial No. 873,559.

To all whom it may concern:

Be it known that I, ISRAEL Mvnns, a citizen of the United States, residing at Goshen, in the county of Elkhart and State of Indiana, have invented a new and useful Automatic Gravity Ladder-Lock, of which the following is a specification.

The object of the invention is to provide novel means whereby relative vertical movement between the constituent sections of a ladder in a downward direction may be prevented, means being provided whereby one section of the ladder may be permitted to move downwardly upon the other section thereof.

In the drawing, Figure 1 shows in front elevation, a ladder constructed in accordance with the present invention, parts being broken away; Fig. 2 is a cross section on the line 22 of Fig. 1; Figs. 3, 4 and 5 are vertical longitudinal sections showing the latch mechanism in different positions.

The ladder comprises a back section 1 and a front section 2, the back section 1 embodying stiles 3 and rungs 4, the front section 2 including stiles 5 and rungs 6. The stiles 5 of the front section 2 are mounted to slide between the stiles 3 of the back section 1. In connecting the sections 1 and 2 together for relative longitudinal movement, a strap 7 extends across the front section 2, and embodies arms 8 passing between the stiles 3 and 5, the arms being held by securing elements 10 to the stiles 3.

A flexible element 11 may be used for raising the front section 2.

The inner face of each stile 5 carries a pivot element 12 upon which is supported the upper end of a latch 14 comprising a head 15 and a depending arm 16. At the rear lower corner of the head 15 there is a depending projection 17. In the arm 16 is a slot 18. Located in the slot 18 is a guard 19 supported intermediate its ends on a pivot element 20 extended across the slot 18 and mounted in the arm 16. ward end 21 of the guard 19 is heavier than the rear end thereof, so that the rear end of the guard is elevated. The bottom portion of the arm 16 below the slot 18 forms a stop adapted to coact with the end 21 of the ard.

WVhen the ladder is in use, the parts appear as shown in Fig. 3. The lower portion 23 of the head 15 rests on one of the rungs The for- 4, the projection 17 lying to the rear of the said rung. The lower end 21 of the guard 19 is in engagement with the stop 22 and the upper rear end of the guard lies in the rear of the projection 17.

The pivot element 12 is so located with respect to the rungs 6 that when the lower portion 23, of the latch 14 is engaged with one rungv4, the rungs 4 and6 on the respective sections are in approximate alinement transversely of the ladder. Thus, when an operator ascends theladder, he treads upon the rungs of both sections. When the section 2 is elevated, the rear edge 24 of the head 15 of the latch engages succeeding rungs 4, thereby tilting the latch 14 forwardly. The section 2, therefore, may be raised to any height. When the latch 14 is swung forwardly, during the raising of the section 2, the projection 17 is adapted to engage one of the rungs 6 to limit the forward swinging movement of the latch. During the raising of the section 2, the upper or rear end of the guard 19 engages successively with the rungs 4, the guard tilting into the position shown in Fig. 4. When the rear upper end of the guard 19 is free from any rung 4, the weighted lower end 21 of the guard assumes the position shown in Fig. 3. When the upward movement of the section 2 is stopped and when the said section is lowered, the latch, having swung rearwardly by gravity, will engage with one rung 4, as shown in Fig. 3. \Vhen the latch 14 swings rearwardly to the position shown in Fig. 3, the arm 16 coacts as shown at 25 with one of the rungs 6 of the front section, to limit the rearward swinging movement of the latch. \Vhen it is desired to lower the front section 2, the section 2 is raised from the position of Fig. 3 to the position of Fig. 4 and then is lowered, the parts assuming the positions of Fig. 5. During the lowering operation, referring to Fig. 5, the upper end of the guard 19 lies to the rear of the projection 17 on the latch and prevents the successive rungs 4 from being engaged by the parts 17 and 23.

In order to stop the section 2 in any position, the same is raised slightly until the rear upper end of the guard 19 hooks beneath one rung 4, and then the section 2 is lowered until the parts 17 and 23 of the latch hook over the rung in question.

The extension 16 of the body portion of the device is ofi'set asshown at Boise that the slot therein may be of a maximum size, thereby to permit the guard to be of sufficient thickness and of su'liicient strength. The guard is provided with an upwardly extend-ed prolongation 51 wherewith the.

forward and rear upwardly converging arms and by a bottom bar uniting the arms,

the bottom bar being provided at its forward end with an integral depending extension, and being provided at its rear end with a depending projection which is shorter than the extension; the extension being equipped with a slot defining a stop at the lower end of the extension; a pivot element mounted in the extension and extended across the slot; a guard located in the slot, the guard terminating at its rear end in a Copies of this patent may be obtained for Having thus described the invention, what reduced; upwardly extended finger prolonged to the rear of the projection, the

guard being provided in its forward end with an integral weight'adapted' to engage the stop and being provided intermediate its ends with. an upward prolongation mounted toswing'on the pivot element; the extension being offset to permit the slot to be of a maximum width, and to permit the guard to be of suflicientthickness; a pivot element uniting the apex of the head with one stile of the forward section, the bottom bar being adapted to engage one rung of the rear sec-- tion, and the finger being engageable by one rung of the rear section to permit a downward swinging of the rear end of the guard.

In testimony that I claim the foregoing as my own, I have hereto affixed my signature in the presence of two witnesses.

ISRAEL MYERS.

Witnesses:

M. V. STARR, L. A. GILMORE.

five cents each, by addressing the Commissioner of Patents. Washington, D. 0. 

